2005 - 2006 Texas Influenza Surveillance Information

The flu activity level for the week ending March 4, 2006 is widespread. Flu activity was reported in all regions of the state.

Reports were received from all 11 Health Service Regions (HSRs) for week 9. An increase in flu activity was reported only in HSR 8. Activity remained about the same in HSRs 2/3, 6/5S, 7, and 9/10. A decrease in flu activity was reported in HSRs 1, 4/5N, and 11. For a map of Health Service Regions, please visit the following website:

A new strain of influenza A named, A/Wisconsin/67/2005-like (H3N2), has been identified from an isolate submitted to The Centers for Disease Control and Prevention (CDC) by the DSHS laboratory in January 2006. The specimen was collected from a resident of Travis County in December 2005. A/Wisconsin/67/2005 is an antigenic variant, which evolved from A/California/07/2004. An A/Wisconsin/67/2005-like virus was recommended by the World Health Organization (WHO) to be included as the H3 component for the 2006-2007 Northern Hemisphere vaccine formulation.

The majority of isolates submitted to CDC by the DSHS lab for further characterization continue to be identified as A/California/07/2004-like (H3N2), which is the H3 component of the current vaccine. A second strain of influenza A named, A/New York/55/2004-like (H3N2), was identified earlier in the season in a resident of Bell County. It has since been identified in a resident of Dallas County. A/New York/55/2004-like (H3N2) is antigenically equivalent to A/California/07/2004-like (H3N2).

Culture confirmed influenza B was identified in Brazos, Dallas, Harris, McLennan, and Travis Counties during week 9. Results on four of the influenza B isolates submitted to CDC by the DSHS lab have come in and indicate that three of the isolates are B/Florida/07/2004-like and one isolate is B/Ohio/01/2005-like. Influenza B viruses currently circulating can be divided into two antigenically distinct lineages represented by B/Yamagata/16/88 and B/Victoria/2/87 viruses. B/Florida/07/2004 is a minor antigenic variant of B/Shanghai/361/2002 and B/Ohio/1/2005 is antigenically equivalent to B/Malaysia/2506/2004.

Overall, the number of flu specimens submitted to the DSHS lab continues to decrease.

Only one influenza outbreak was reported during week 9 in a high school in Erath County (HSR 3).

For more information on flu surveillance activities in the State of Texas, please visit the following website: